Sand Filter-- The Basics a Pool Owner Should Know Before and After Buying Pool Sand Filters
Maintaining the cleanliness of a pool with a sand filter is generally ideal for pool owners who want a highly thorough filtering system. Pool filters are available in three types: one is sand, and the other two is Diatomaceous Earth (DE), and cartridge. While a cartridge filter will give you the least cleanest water and maintenance, and a DE cartridge will give you the cleanest water with the most maintenance, the pool sand filter will give you results in between. Keep in mind that using a sand filter does require a little extra maintenance.
How pool sand filters work
put, sand filtration works by passing water through the filter media
via a diffuser, and exiting the bottom of the filter in a cleansed
state. The filter media is made up of specially graded sand. This
particular type of sand has particles that are ground into 45 to 55mm
in diameter. This size is fine enough to allow water to pass through,
but it is rough enough to trap debris. As the water flows down through
the bed of sand, dirt and debris gets trapped. When the cleansed water
exits through the bottom of the filter, it is then returned to the pool
through lateral tubes at the base of the filter.
Sand filters do have a few limitations. Sand can filter debris down to approximately 40 microns; anything smaller probably will not get filtered out. Sand filtration can also help reduce the need for harsh chemicals, but some chemicals will need to be used in the filtered water to kill bacteria and mildew.
Where to buy and the cost of pool sand filters
Pool sand filters are readily available at local pool maintenance
shops, and online with a variety of reputable vendors. Depending on
the size of the filter, how it is mounted, and the manufacturer's
reputation for quality, a filter can cost as little as $200 to over
$600. Hayward filters are a very popular, highly regarded, and most
expensive pool filter brand, but there are other brands such as
Sta-Rite and AquaQuik that have adequate quality at lower prices.
How Often Does This Filter To Be Replaced?
pool maintenance experts say that a sand bed should be replaced
every 5 to 7 years. The gradual loss of efficiency may not be easily
noticeable. When the filter is new the grains are rough, which is
important to the efficiency of processing clean water. With continued
use, the grains lose this rough quality essential to allowing the
filter to efficiently process
clean water. If your filter requires frequent backwashing, this can be
a sign of calcium build-up, "mudballing", or "channeling". Using
biguanide chemicals to clean the filter annually prevents the sand from
building up from the mixture of the sand and bodily oils.
Sand filter troubleshooting
Using a sand filter can give it's share of headaches, and you may
encounter some problems from time to time. Here are some of the most
common troubleshooting tips for pool sand pump filters:
- Sand at the bottom of the pool-- This can be the effect of several problems. First, you could possibly using sand that is too small; if this is the case, remove the sand and replace with #20 silica or 45-55mm pool sand. This can also be an indication of a broken lateral or standpipe, which you will need to empty the tank, repair, and then refill the sand. Another possiblity is that there can be a loose lateral pipe, which can be fixed by tightening. Lastly, your pump may be too big for your filter. Refer to your pool manufacturer's instructions to make sure you have the correct size.
- The filter is too noisy-- Excessive flow from a large pump may cause noise in the filter valve. You can test this by partially placing your hand in front of the returns at the pool wall. If this muffles the noise, this means that the problem is indeed excessive flow, which can be fixed by installing smaller eyeball fitting, changing the pump impeller size, or changing to a two inch control valve.
- The filter is running in short cycles-- This can be the result of improper backwashing. You may also have algae clogging the filter. You can remedy this by testing the water balance and chlorinating.
- The water in the pool won't stay clear-- There are several reasons why this may be the case. The undersized piping may be clogged and needs to be cleaned. Your pump may be installed incorrectly, causing the filter to run in reverse. The pool chemistry may be off, allowing algae to grow. You may also be backwashing too often. You should backwash only when the pressure rises to 7 - 10 psi over the starting pressure or when the return flow back into the pool becomes low.
- Sand filter is running at unusually high pressures-- This
can be due to clogged mineral deposits that will not backwash away,
clogging the sandbed. Refer to the manufacturer's backwashing
instructions, backwash, and change the sand more often. It is possible
that you may have to clean your system with special filter cleaner.
Your pump may also be too small, hindering the flow for backwashing.
Fix this by checking the output of the pump to make sure it is equal to
your filter's flow rate. If you find the pump is too small, replace it.